Capping and de-capping apparatus and a method of operating such an apparatus

Abstract

A capping and de-capping apparatus for capping and de-capping tubes disposed in a tube holding rack having a two-dimensional array of apertures for holding the tubes. The apparatus comprises a rack support for supporting the tube holding rack, a head unit adapted for carrying a cartridge comprising at least one capping and de-capping gripper, a drive system for moving the rack support and the head unit relatively towards and away from one another, in order to cause engagement or disengagement of the capping and de-capping gripper with or from a cap of at least one tube, and a drive system for rotating the capping and de-capping gripper, wherein rotation in one direction causes attachment of the cap to the tube and rotation in the opposite direction causes detachment of the cap from said tube.

What is claimed is: 
     
         1 . A capping and de-capping apparatus for capping and de-capping tubes disposed in a tube holding rack having a two-dimensional array of tubes, the apparatus comprising:
 a head unit carrying an array of rotary actuators and an array of ejector pins coaxial with the rotary actuators;   an exchangeable cartridge including an array of capping and de-capping grippers, each gripper to engage a cap on a tube, the cartridge being configured to attach to and detach from the head unit, the cartridge permitting exchange of an entire array of capping and de-capping grippers at once for rotation of the grippers; and   a drive system that effects translational movement of the ejector pins relative to the grippers;   the head unit and the cartridge configured, when attached, to engage the rotary actuators with the capping and de-capping grippers as the ejector pins pass axially through the capping and de-capping grippers, wherein the grippers are rotated by the rotary actuators but are coupled to permit translational movement of the ejector pins through the grippers, rotation of a rotary actuator and gripper in one direction causing attachment of a cap to a tube and rotation in the opposite direction causing detachment of the cap from the tube, and translational movement of the ejector pins through the grippers effecting release of caps from the grippers.   
     
     
         2 . The apparatus of  claim 1 , wherein the head unit includes a first support frame and a second support frame, the cartridge being attached to the second support frame. 
     
     
         3 . A capping and de-capping apparatus for capping and de-capping tubes disposed in a tube holding rack having a two-dimensional array of tubes, the apparatus comprising:
 a head unit carrying an array of rotary actuators; and   an exchangeable cartridge including an array of capping and de-capping grippers, each gripper to engage a cap on a tube, the cartridge being configured to attach to and detach from the head unit, the cartridge permitting exchange of an entire array of capping and de-capping grippers at once for rotation of the grippers;   the head unit and the cartridge configured, when attached, to engage the rotary actuators with the capping and de-capping grippers, wherein the grippers are rotated by the rotary actuators, rotation of a rotary actuator and gripper in one direction causing attachment of a cap to a tube and rotation in the opposite direction causing detachment of the cap from the tube.   
     
     
         4 . The apparatus of  claim 3 , wherein the head unit includes a first support frame and a second support frame, the cartridge being attached to the second support frame. 
     
     
         5 . The apparatus of  claim 3 , further comprising an ejector assembly and a drive system that effects translational movement of the ejector assembly relative to the grippers to effect release of the caps from the grippers. 
     
     
         6 . The apparatus of  claim 3 , wherein the rotary actuators are operated independently such that each capping and de-capping gripper may engage or disengage a cap independently of the other grippers. 
     
     
         7 . The apparatus of  claim 6 , further comprising a control unit configured to permit a user to decide which capping and de-capping grippers engage or disengage tubes. 
     
     
         8 . The apparatus of  claim 3 , wherein the cartridge is attached to and detached from the head unit via automated clamping means. 
     
     
         9 . A method of operating a capping and de-capping apparatus according to  claim 3 , the method comprising:
 placing a cartridge onto a rack support;   moving the head unit and the rack support toward each other by means of a drive system;   attaching the cartridge to the head unit;   moving the head unit and the cartridge from the rack support by means of the drive system;   placing a rack onto the rack support;   moving the head unit and the cartridge towards the rack and the rack support by means of the drive system;   with at least one capping and de-capping gripper, attached to the cartridge, engaging an opposing cap on an opposing test tube placed in the rack on the rack support; and   disengaging the cap from the test tube by means of (i) concerted movement of the drive system, (ii) moving the head unit away from the rack support, and (iii) a simultaneous rotational movement of the gripper unit, the rotational movement being caused by a rotary actuator.   
     
     
         10 . The method of  claim 9 , further comprising:
 attaching a cap, by means of reversing the above steps, the rotational movement being stopped when a certain threshold torque is exceeded.   
     
     
         11 . The method of  claim 9 , further comprising detaching the cartridge from the head unit by:
 moving the head unit and the cartridge towards the rack support by means of a drive system such that the cartridge rests upon the rack support;   detaching the cartridge from the head unit; and   moving the head unit from the cartridge and the rack support by means of the drive system.   
     
     
         12 . The method of  claim 11 , wherein the cartridge is attached to and detached from the head unit via automated clamping means. 
     
     
         13 . The method of  claim 9 , wherein a cap in contact with a capping and de-capping gripper, but not undergoing a rotation by a rotary actuator, is not removed from a respective test tube. 
     
     
         14 . The method of  claim 9 , further comprising:
 releasing a capped tube from a capping and de-capping gripper by moving a first attachment body towards the rack support such that an ejector comes into contact with the cap of the tube;   disengaging the gripper from the cap by moving a second attachment body away from the tube, whereby the ejector remains in contact with the cap while the gripper is disengaged from the cap; and   moving the first attachment body from the rack support, thereby releasing the tube and freeing the capping and de-capping apparatus to perform a new cycle of capping and de-capping.